Here is the full list of all 66 Alien Swarm achievements.
Kill 100,000 Swarm.
Kill 25,000 Swarm.
Complete Timor Station within 4:25 on Normal difficulty or harder without any marines dying.
Complete Sewer Junction within 1:30 on Normal difficulty or harder without any marines dying.
Complete SynTek Residential within 2:30 on Normal difficulty or harder without any marines dying.
Complete Rydberg Reactor within 3:10 on Normal difficulty or harder without any marines dying.
Complete a campaign on Normal difficulty or harder without any marines dying.
Complete any mission on Brutal difficulty with Onslaught and Hardcore Friendly Fire enabled.
Complete 10 computer hacks without access being logged.
Kill 15 Swarm with all four marines under the effects of a Damage Amp in a single mission.
Complete Deima Surface Bridge within 2:30 on Normal difficulty or harder without any marines dying.
Complete Cargo Elevator within 2:50 on Normal difficulty or harder without any marines dying.
Complete Landing Bay within 1:25 on Normal difficulty or harder without any marines dying.
Awarded for finishing the Jacob campaign on Brutal difficulty.
Awarded for finishing the Jacob campaign on Insane difficulty.
Complete a mission with no friendly fire incidents. Four marines must be present in the mission.
Deploy 10 ammo stashes that are used by other marines.
Complete a mission on Normal difficulty or harder without receiving any damage.
Destroy all Swarm Eggs in a mission without allowing any to hatch.
Kill 100 Swarm Grubs.
Complete 10 wire hacks without access being logged.
Kill 5 Swarm with explosive barrels in a single mission.
Kill 250 Swarm with a Grenade Launcher.
Kill 5,000 Swarm.
Stun 6 Swarm with a single Stun Grenade.
Kill 250 Swarm with a Marksman Rifle.
Kill 250 Swarm with a Rail Rifle.
Kill 250 Swarm with a Flamethrower.
Kill 250 Swarm with a Tesla Cannon.
Kill 6 Swarm with a single Grenade.
Kill 250 Swarm with a Chainsaw.
Kill 100 Swarm with Incendiary Mines.
Freeze 6 Swarm with a single Freeze Grenade.
Kill 100 Swarm with Hornet Barrages.
Kill 500 Swarm with deployable Sentry Guns.
Kill 250 Swarm with a Minigun.
Kill 250 Swarm with PDWs.
Kill 250 Swarm with a Vindicator.
Kill 250 Swarm with a Shotgun.
Kill 250 Swarm with an Autogun.
Kill 100 Swarm with Laser Tripmines.
Kill 250 Swarm with a Prototype Rifle.
Complete a mission with better than 90% accuracy.
Kill 250 Swarm with Twin Pistols.
Seal a door with the welder.
Unlock all the available weapons.
Kill 1,000 Swarm.
Guard the squad's tech so that he takes no damage during the hack.
Complete the Jacob's Rest campaign on Hard difficulty or harder.
Heal 300 points of damage in a single mission without dealing any non-melee damage to the Swarm.
Kill 20 Swarm with melee attacks in a single mission.
Complete the Jacob's Rest campaign on Normal difficulty or harder.
Complete the Jacob's Rest campaign on Easy difficulty or harder.
Roll under a Swarm Ranger projectile.
Kill 250 Swarm with the Assault Rifle.
Deliver the finishing blow to a Swarm Shieldbug.
Kill a Swarm Parasite with a melee attack.
Cure an Infested marine.
Kill a Swarm Boomer before it inflates.
Kill 25 drones without friendly fire. Four marines must be present in the mission.
Complete a mission on Normal difficulty or harder without any marines dying.
Complete 2 co-op missions online. Earns a Team Fortress 2 parasite hat.
Successfully perform 5 fast reloads in a row.
Heal all 4 marines with a single Heal Beacon.
Successfully perform a fast reload.
Finish a mission without the tech getting killed.